Improvement in sheet-metal elbow-joints



UNITED STATES PATENT Crrrcn.

JOSEPH S. DENNIS, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN SHEET-METAL ELBOW-JOINTS. I

Specilication forming part of Letters Patent No. 151,103, dated May 19,1874 application filed April 11, 187i.

To all whom it may concern:

Be it known that I, JOSEPH S. DENNIS, of Chicago, Illinois, haveinvented certain Improvements in Elbow-Joints for Sheet-Metal Tubing andPiping, of which the following is a specification:

This invention relates to a novel elbow-joint for all kinds ofsheetemetal tubing or piping.

My invention is intended to facilitate and cheapen the making of elbowsfor sheet-metal tubes, as well as to improve the appearace of the same 5and it consists of a pipe-elbow formed by joining two curved ends, eachof said curved ends forming one-half of the elbow, as will be fullyunderstood by the following description set-ting forth the method ofconstruction which I prefer to employ, and having reference to theaccompanying drawings, in which drawing- Figure l represents a view ofthe former or blank before the tube is rolled. Fig. 2 represents a side,front, and rear view of the tube after itY is rolled, and before thecurve is formed; Fig. 3, a side, front, and rear view of the same afterthe curve is formed. Fig. 4 is a view of the same blank as Fig. 1,except that the line of union is at the opposite side of the tube whenrolled. Fig. 5 is a side, front,yand rear View of this latter blank whenrolled into a tube 5 Aand Fig. 6 is a side, front, and rear view of thesame after the curve is formed. Figs. 7, 8, and 9 "are views of theelbow-joint complete, illustrating the different angles at which thesame parts may be joined.

The blanks for the tubes are first cut by dies or other suitable meansinto the form substantially as shown at Fig. 1 or Fig. 4, the differencebetween the two being simply that in Fig. l the lap or fold, where theedges of the blank come together to form the tube, is located on theoutside of the curve or elbow, and in Fig. 4 it is on the inside of thecurve or elbow; it is sometimes convenient to have it upon one side andsometimes upon the other. In all other respects the two blanks are thesame. In these blanks it will be noticed the end at which the half-elbowis to be formed is shaped with the curve a c and the curve b b, (shownin the drawing ,l the form may be somewhat varied, but I deem thepattern` given in the drawing the best. The blank is rolled into a tube,as shown at Figs. 2 and 5, and it may be now, as at a future stage,soldered at the lap' c; or, in case of large piping, the edges may bejoined by the common pipelap fold, or riveted. The metal at the end isthen bent, by any suitable mechanical means, until the curves b b comein contact, and the curves c a are brought into a circle lying in planeoblique tothe axis of the tube-in other words, until a half-elbow isformed at the end of the tube, as shown at Figs. 3 and 6. Two of thetubes, each formed thus with a half-elbow, are united to form a completeelbow-joint, by thrusting one within the other as far as muy be desiredto give the proper angle. It may be best in making elbows for stovepipes, where it is impracticable to solder the parts together, that theblanks for the two limbs of the joint be made slightly different fromeach other, by varying the position of the line of union or lap wherethe tube is seamed, so that the slit or ununited edges of the curves I)b shall not register when the two half-elbows are joined. This, however,would seem to be a matter to be left to the judgment of the workman. Thetwo limbs of the joint may be united, as is indicated in Figs. 7 8, and9, at various angles 5 this proves a great converience in fitting up anykind oftubing or piping.

This joint may be made very cheaply, and

wholly by machinery, if desired, and is muchV easier to make, andpresents a more elegant and shapely appearance, than the common miteredjoint or the corrugated joint.

Having described my invention, I claim as new and desire to secure byLetters Patent- A sheet-metal elbow formed of two curved ends of a tubecupped together, substantially as specified.

J. S. DENNIS. Witnesses:

JOHN W. MUNDAY, HEINRICH F. BRUNS.

